<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>
<script>
  console.log(Array.prototype)
  const ret = {age: 19}
  const list = [{age: 15}, ret, {age :16}, {age: 19}, ret]


</script>
</body>
</html>
